Brandenburg-Prussia

Brandenburg-Prussia was a state of the Holy Roman Empire that existed from 1618 to 1701, with Berlin and Koenigsberg serving as its capitals. The state was formed as a personal union of the Margraviate of Brandenburg and the Duchy of Prussia, and it included lands as far east as East Prussia and as far west as the Habsburg Netherlands. The state changed sides three times during the Thirty Years' War, leading to widespread devastation in the country. Over half of the population was killed or dislocated, and the recovery from the destruction of Prussia's cities took decades. In 1648, Brandenburg-Prussia gained Minden and Halberstadt, and its territories were expanded as it fought in the "Northern Wars" against Sweden. In 1653, Prussia formed its own standing army, and it was involved in the wars against Poland-Lithuania during The Deluge of 1655-1660, defeating the Poles at Warsaw in 1656 before defeating Sweden at Fehrbellin in 1675 during the Scanian War/Franco-Dutch War. The state also managed to establish colonies in the Gold Coast and on Arguin (off the coast of Mauritania). In 1701, Brandenburg-Prussia became the independent kingdom of Prussia after Friedrich I of Prussia proclaimed himself "King in Prussia", remaining only a nominal vassal of the Holy Roman Empire.